I checked that statement about the torque converter with Dave Pook (one of the XKR 75, R-S and R-S GT team) when i interviewed him for my article on the 75. I'm fairly sure he confirmed it, but: I've checked the notes I made against each of the bullet points in my list, and there's no comment against the torque converter one.

So, nope, I have no proof. I know that ZF does have a range of different components that manufacturers can select, and they're supposedly (more or less) interchangeable. And I did read that the original XKR was limited to 510 PS and 625 Nm because the converter would have been overstressed by higher output. As is normal for such things, that does not mean that it would have broken, just that it would reduce the fault-free life.

But the fact that there's only one part number regardless of the model suggests that this ain't so. Perhaps it was just marketing-speak for a change to the TCM code to modify the gearbox operation, as Steve says. Dave was more involved in the suspension/steering/handling side, so he may not have known the detail. The only other possibility is that Jaguar simply standardised on an uprated part, so that if you order a replacement converter, you get the 'better' part rather than whatever is fitted to your car. However, they didn't do that for other stuff like the update water pump, so it's unlikely.

 

For what its worth, attached are extracts from articles on the XKR 75 and XKR-S from 2010 and 2011 editions of Jaguar World. Both mention the upgraded torque converter.

 

To add to the confusion, here is another link with ZF gearbox/TC info, it shows 2 TC versions for the 5.0SC, a B110 and J134

https://ci-portal.zf.com/global/medi...nsmissions.pdf

 

Interesting, the B110 applies to multiple SC models (XJ, XF and XKR) with the 6HP28 transmissions, but the J134 appears only on 3 of the 5.0L XKRs, it also has a unique part number 4168 027 106.

 

Here it shows as specific for the XKR-S

 

I'm surprised there isn't more talk here of first upgrading the exhaust on the XKR before doing a tune. I might be too old-school, but I grew up understand that, dollar-for-dollar, exhaust mods are the best (and first) performance mods to make, and that was certainly true with the GM engines I got to know.
And it seems to be supported by Jaguar's installing upgraded exhaust standard on the XKR-S. Bottom line for me: no way would I invest in a tune until I'd swapped out for that X-pipe setup on the XKR-S first.

 

And here's a nutty thought that will undoubtedly earn me much jeering here on the thread, but:

Has anybody asked a dealer to do it? Given that we keep referencing the XKR-S, why not ask, out of curiosity: "If I had you guys swap out my exhaust for the XKR-S setup, would you be willing to retune both the ECM and TCM to XKR-S specs, and what would be the price on that?"

Just curious.

 

PK from what I understand the Performance Active Exhaust (PAE) is the X-Type system used on the XKR and XKR-S . I would like to see what is under the GT
Here's my 2012 XKR

 

Most dealers would probably be willing to install a factory x pipe, I've seen it done locally, but as far as software they will only flash what was specified by the VIN, too much liability for one thing if something went wrong and they bricked a module and I also suspect most would not even know how to access the upgraded files within SDD since the software also flashes by VIN. They would have to know what file belongs to the "S" model and know how to flash it as SDD does not provide that option directly.

 

By the way I ask my dealer 2 weeks ago during my annual oil change what the difference was between my XKR vs the same year XKR-S. Hie service manager came out and told me that the only difference was the tune as long as I had the PAE. He also told me (when I asked) that Jaguar would not allow loading the XKR-S tune into an XKR. The tune has to fit the SN. Also the the new F-Type SVR at 575 HP has a different smaller pulley for the extra 25HP

 

But that was an option, right? I don't think I've got that setup on mine. Wish I did. As far as I can tell that exhaust setup and the different tune are the main power differences between the two..

 

Yes the PAE is listed on my window sticker as a $1400 option.

 

PAE was only standard on the 75, R-S and Dynamic R; it was an option on the R from after the 75 (2011).

And, yes, the SDD application only allows loading of software (for any module) that is approved for the VIN. There are tuning companies that will load non-standard fuel maps and possibly even the R-S ECU software, but you're out of luck if you want uprated transmission or other loads. Which is a pain, because I'd really like mine to get the R-S EAD and DSC software, which the 75 missed out on because of time/money constraints (the hardware is identical).

 

This whole topic about the transmissions, torque converters, TCM, etc, has been doing my head in. It's hard to know what to believe, and not easy to find answers without plugging an SDD into all the different cars, and physically checking part numbers...

But I think I've figured it out. After going through various documents from JLR, ZF, and cross-checking, also checking some data from cars i've worked on, it's making sense to me now.

Turns out, there are actually three different ZF 6-speed transmissions that were used in the 5.0L supercharged X150's...

In the 2010MY the transmission was actually a 6HP26 (from VIN B32753 to VIN B38853). And then in the 2011MY (from VIN B38854) this was changed to a 6HP28. The same torque converter was used for both the 6HP26 and later 6HP28, the B110 unit seen in the ZF documents. This is the one shown in the JEPC parts catalogue i.e. "there is only one torque converter". According to ZF documents there were 4x internal revisions of the 6HP26 used on the 2010MY 5.0L XKR, this appears to be related to programming, as I can see from the TCM software parts numbers there were a number of revisions.

The mechatronic in the 5.0L 6HP26 was different to the one in the 5.0L 6HP28. Therefore the TCM software is also "different" but it's easy to miss, only one letter different 9W83 vs 9X83, same like the hardware part number changes for the transmissions themselves.

The 6HP28 in the XKR continued from MY11 right up to the end of the X150 production, some software revisions, 3x internal revisions from ZF.

Getting back to the question of the XKR75, well it was launched in June 2010. I'm not sure of the build dates of the actual cars exactly, or the VINs, so are they MY10 or MY11 cars? Far as I can see it's MY10...

2010MY from B32753 to B38853
2011MY from B38854 to B44939
2012MY from B44940 to B48619
2013MY from B48620 to ???? (i've seen ~55000 on one local car)

What's interesting is that when you select a 2010 XKR in Topix it gives you the choice of either a 6HP26 or 6HP28



So i'm thinking, the XKR75 got the 6HP28 from the 11MY "early" and that's where this story about an uprated transmission or torque converter came from?

Now regarding the XKR-S...

So the XKR-S was a 2012MY car, but it was launched in March 2011 at the Geneva motor show. I don't know if it was really production ready at that stage or not. I think what's happened is they did the 550PS/680Nm engine tune around that time, and after some longer term tests came to realise that the standard 6HP28 was not up to the task, especially in a "hardcore" car like the XKR-S, which is going to be driven hard.

Also at around this time JLR was switching to the 8HP70 8-speed, so the 6HP28 that was carried on in the X150 was kind of an orphan. What's interesting to note here is that the F-Type has two different variants of the 8HP70 for the V8 models, one for the V8S which is noted as "625Nm" and the other noted as "680Nm". The "680Nm" version 8HP70 is the same one used in the XFR-S, and the X351 XJR. Both of those being 550PS/680Nm tuned, like the XKR-S. You see the pattern forming here?

There is a different version of the 6HP28 for the XKR-S compared to the regular XKR. It's different part numbers for the complete transmission, as shown by ZF and Jag.
There is a different torque converter for the XKR-S version of the 6HP28 (the J134 version), it's shown in ZF's documentation, but there is no mention of it in the JEPC or other Jaguar documentation I can find. I do not think this is the same torque converter as some press release / media documents mention about the XKR75, and i'll explain why later. The dates don't match up.

The mechatronic in the XKR-S 6HP28 is the same unit as the regular XKR 6HP28, but different to the mechatronic in the 2010MY 6HP26.

There are two software files or "parts" for the TCM program. A primary and a secondary.
The primary software part is the same for the 6HP28 in the XKR and the XKR-S. The secondary is different (I missed this before).

The part number of the secondary TCM software file is matching to the part number of the complete transmission. Let's call it BW8M for the XKR-S version in this discussion.

This J134 torque converter is only used with the XKR-S 6HP28, according to ZF documentation.
The secondary software part for the XKR-S is not used with the XKR either.

You could say that the J134 Torque Converter and the BW8M TCM file go together.

I tried to find the the earliest revision of the BW8M TCM software by looking in older versions of SDD, it's not there in V125 of March 2011, it's there in V129 however, and the date of the file creation is 1st Feb 2012, although that's not the first revision. I'm trying to get hold of V126, V127 & V128 to see what TCM files are in those versions. But since it's not there in V125, it means it's extremely unlikely that an XKR75 built before March 2011 could have the "XKR-S spec" transmission & torque converter, since JLR had to put the software parts in the IDS/SDD for a production vehicle, and software parts for mules and test cars ended up in there as well.

It makes sense to me after putting all these pieces together that a 2010MY XKR75 got the regular 6HP28 from the 2011MY, and the standard XKR's in 2010MY got the 6HP26, which would still mean the XKR75 had an "upgraded transmission" compared to the other 2010MY XKR's, but the same torque converter. And not a "special" TCM tune, just the same tune as the 2011MY XKR. Not the XKR-S.

 

You can flash the XKR-S engine tune to any 5.0L XKR, from 2010MY onward, using SDD. I have done two of them. An authorised Jaguar dealer is forbidden from doing this. Not allowed. Full stop.

You should do the XKR-S tune in conjunction with the Performance Active Exhaust, since actually the exhaust has more to do with the increase in power than the tune alone.

My ex-JLR tuner contact analysed the XKR and the XKR-S factory tunes to see the difference, the XKR-S has a raised torque limiter, and some very small tweaks to some other (apparently) insignificant tables.

Problem now is that to buy a PAE as a spare part (the centre section and the rear box separately) you have to provide a VIN of a car that was factory fitted with the PAE, and in some cases, Jag will ask for photos of the damaged parts that you have to replace. The price for the parts is also eye-watering...

I see complete XKR-S exhausts on ebay.uk from time to time, I presume people are fitting aftermarket exhausts and flogging off the originals to recover some costs.

Jaguar XKR 75 / XKR-S 5.0 Performance Active Exhaust X-Pipe - RRP £800 | eBay

If you have the 6HP28, then it's probably possible to flash the TCM software from the XKR-S in. But I don't know if it's a good idea or not...

The other stuff like the E-Diff and ABS, may also be possible, i'd need to look further into it.

I'm aware of the XKR-S GT having a different ABS/DSC program than the regular XKR-S and XKR, that could be interesting...

 

Just as a side note, the highest confirmed MY 2015 XKR VIN I have seen is 56722.

 

Good reasoning, Cambo - but the 75 is an MY11 car. It wasn't built until September 2010, and my VIN is well into the MY11 range (B42...). That means it definitely has the 6HP28 transmission, like all other MY11 XKRs - that wasn't a special build. And the 28 has so many other advances over the 26 that they would have trumpeted those at the 75's release.

I'm running purely on recollection here, because there's nothing in my notes, but I think I was told that the converter in the 75 carried on into the R-S, along with all the other uprated components. Basically, the story from Dave Pook was that the 75 & R-S are (almost) mechanically the same; the software builds and bodywork are different. With the 75, they ran out of time & money so some stuff stayed XKR-stock, like the EAD and DSC software and the rear exhaust box. Other software & tuning elements received extra tweaks for the R-S.

That would suggest that the 75 has the same J134 converter as the R-S. As you have access to TOPIx, which I no longer seem to have, PM me and I'll give you my VIN so you can look it up & see what part no. it gives for the converter.

 

Sorry, I guess I was misinformed - I was told that SDD insisted on having the VIN, and put a check-code into the software load that was related to it so that it would only work on that VIN. But I guess it's more of a procedural thing.

Ooooo - most interesting! Does that mean that any car with the PAE option has significantly more than 510PS? I knew that the PAE contributed a power increase but was given the impression that most of the increase in the 75 & R-S was down to engine maps.

I made some enquiries with tuning companies after learning that the other R-S module tunes would work on the 75, but I could not find anyone who said they could load anything other than ECU maps. Dave P said the 75 would gain some benefit from the R-S Active Dynamics tune, but more from the EAD and DSC. So I'd love to find some way to achieve it.

 

Ah ok, but that leaves another mystery, why is there an option in Topix for either 6HP26 or 6HP28 for the 2010MY, when all the parts listings show only the 6HP26 for that year...

The problem is, that hardware changes without the corresponding software changes are very hard to determine. Pretty much the only way to find out is put the 75 up on a hoist and read the part numbers off the label on the transmission, and where they are located you'd probably need a borescope and mirror to see the damn things...

Topix does not give a list of parts by part number that were put into a car. Generally this can be worked out using SDD based on software versions. But again if there were hardware changes but no software changes, nobody can tell without physically checking the parts on the car.

One could assume that the J134 torque converter was only fitted in conjunction with the BW8M version of the 6HP28, like in the XKR-S. So if the 75 has the BW8M 6HP28, then that's a confirmation.

If the J134 torque converter was fitted to the 75 with the standard 6HP28 of the XKR, not the BW8M version, then you would need to physically check the torque converter itself for numbers stamped on it by ZF. I don't see any other means of finding out for sure.

 

Yes you need to go outside of the standard procedure in order to flash the XKR-S tune to an XKR.

The tune and the exhaust work together. The PAE exhaust flows better, and the tune has the limits raised in order for the engine to make the most of that improvement.

Conversely, the stock XKR engine tune has torque limiters in place, so even if you improve the exhaust, intake, pulley's, once the engine output reaches that limit, that's as far as it will go, and it will throttle back to hold that limit.

Maybe there is enough head room in the stock XKR tune to get some gains from the PAE, I don't know exactly. Depends on your definition of "significant" I guess. But from what i've been informed, any major mechanical changes are not going to bring you gains without the tune being modified accordingly.

It is possible with SDD, a similar process as putting the R-S engine tune in an R, but again dealers are forbidden to do it, and you need to do some workarounds in order to flash different software to a module.

The aftermarket tuners are limited by their tools, which only work with engine ECU's. SDD can flash any module in the car.